Thread (12 messages) 12 messages, 5 authors, 2015-10-21

Re: [PATCH net-next 2/2] xfrm: Fix unaligned access in xfrm_notify_sa() for DELSA

From: Sowmini Varadhan <hidden>
Date: 2015-10-21 10:55:09
Also in: linux-crypto, lkml

On (10/21/15 08:57), Steffen Klassert wrote:
quoted
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -2659,7 +2659,7 @@ static int xfrm_notify_sa(struct xfrm_state *x, const struct km_event *c)
 		if (attr == NULL)
 			goto out_free_skb;
 
-		p = nla_data(attr);
+		p = PTR_ALIGN(nla_data(attr), __alignof__(*p));
Hm, this breaks userspace notifications on 64-bit systems.
Userspace expects this to be aligned to 4, with your patch
it is aligned to 8 on 64-bit.

Without your patch I get the correct notification when deleting a SA:
But __alignof__(*p) is 8 on sparc, and without the patch I get
all types of unaligned access. So what do you suggest as the fix?

(and openswan/pluto dont flag any errors with the patch, which is
a separate bug).

--Sowmini
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